Powder-actuated tool

ABSTRACT

A powder-actuated tool especially adapted for use in driving fasteners to attach insulating board to ingot molds. An operating handle is attached to an elongated handle of the tool. Upon downward movement of the operating handle, the tool is cocked as well as a fresh cartridge inserted into a three chamber cartridge receiving turret from a cartridge belt and the turret member partially indexed. Upon upward movement of the operating handle, the turret is completely indexed, a spent cartridge is removed from one of the chambers into the belt, and the cartridge belt is indexed. The tool cannot be fired unless the barrel is in its rearward position. A mechanism is included to prevent less than the full amount of movement of the operating handle in any direction before it can be reversed.

United States Patent Hodil Dec. 30, 1975 [54] POWDER-ACTUATED TOOL Primary ExaminerGranville Y. Custer, Jr. [75] Inventor: Elmer R. Hodil, Brant'ord, Conn. Attorney 4 f firmwDomld Motsko;

Samuel K1eser; William W. Jones [73] Assigneez Olin Corporation, New Haven,

Conn. 57 ABSTRACT [22] F1led: Aug. 5, 1974 1 A powder-actuated tool especially adapted for use in [21] Appl' 494663 driving fasteners to attach insulating board to ingot molds. An operating handle is attached to an elon- 52 us. c1. 227/10; 227/121; 227/136 gated handle of the toolp downward movement 51 int. c1. B25C 1/14 of the Operating handle, the tool is cocked as well as a [58] Field of Search 227/8 9 10 11 121 fresh cartridge inserted into a three chamber cartridge 227/136 receiving turret from a cartridge belt and the turret member partially indexed. Upon upward movement of [56] Referen Cit d the operating handle, the turret is completely indexed, UNITED STATES PATENTS a spent cartridge is removed from one of the chambers into the belt, and the cartridge belt is indexed. The gii ifiz tool cannot be tired unless the: barrel is in its rearward 3:632:032 1/1972 iz: 22) .position. A mechanism is included to prevent less than 3 43 350 2 7 Endo at i 227,8 1 the full amount of movement of the operating handle 3,679,l l8 7 1972 Maier et al. 227 10 in y direction before it can be reversed- 3,743,159 7 1973 Schneider 227 10 1 21 Claims, 14 Drawing Figures Em l 1 /IZ /60 1 j i l x a i T 15 4 1 a 4/ 1/ I, l 97 45 me x 95 j a I 4 7 j 1 4 I 1 7! Z US. Patent Dec.30,1975 Sheet 1 of5 3,929,269

34 zzo US. Patent Dec. 30, 1975 Sheet 2 of5 3,29,26

US. Patent Dec. 30, 1975 Sheet4 0f5 3,929,269

@w w QM US. Patent Dec. 30, 1975 Sheet 5 of5 3,929,269

POWDER-ACTUATED TOOL BACKGROUND OF THE INVENTION This invention relates to powder-actuated tools for use in driving fasteners or the like into or through a particular work surface. More particularly, this invention relates to a powder-actuated tool which is especially adapted for affixing insulating panels to ingot molds, although some of the features incorporated in the particular tool described herein may be used in other types of powder-actuated tools.

It has been the practice of industry to attach heat insulating boards at the inside of the upper end of an ingot mold to provide a heat insulating liner or hot top for the purpose of maintaining a reservoir of hot metal on top of the ingot during solidification. It is necessary that these insulation panels be firmly attached to the ingot mold so that they are maintained in proper position during the pouring operation as well as transporting of the mold.

Sometimes prior to the present invention, these insulating boards were attached to the ingot molds by means of various types of fixtures such as inverted U-shaped resilient clamps. More recently, it has become the practice to affix such insulating boards to the ingot mold by means of fasteners driven by a powderactuated tool. While there are many types of conventional powder-actuated tools which are used to set fasteners in the various types of work surfaces, tools to be used in connection with the setting of insulating boards and ingot molds are somewhat unique in the sense that they require a long handle so that a man standing on the mold can position the fastener-driving portion of the tool within the mold cavity. The toll must also be capable of being actuated from a point remote from the fastener-driving portion. In addition, it is necessary that the cartridge case be completely contained during the loading, firing and extracting operation to eliminate the possibility of a case inadvertantly falling into the mold.

SUMMARY OF INVENTION One of the objects of the present invention is to provide an improved powder-actuated fastener-driving tool which can be actuated at a considerable distance from the fastener-driving portion of the tool itself.

Yet another object of the present invention is to provide a powder-actuated tool having sufficient safety features to allow it to be used for fastening insulating boards to ingot molds.

Still another object of the present invention is to provide a powder-actuated tool having an improved cartridge feeding and extracting assembly which insures that the cartridge case is completely contained at all times.

A further object of the present invention is to provide a remotely actuated powder-actuated tool which requires a minimum amount of operation by the user of the tool.

A still further object of the present invention is the provision of a powder actuated tool having a cocking and firing mechanism designed to prevent the accidental firing of the tool.

Theseand other objects of the present invention may be realised according to the preferred embodiment of the present invention through theprovision of a tool which utilizes a housing member having an elongated handle extending therefrom through which a trigger rod extends. The trigger rod can only fire the tool when the tool has been properly positioned against the work surface.

The trigger rod is connected to a sear member through a trigger bar link in such a manner that the axes of the trigger rod and trigger bar are offset and are attached to the trigger bar link which rotates about a fixed point. The moment of the trigger rod and trigger bar are equal to minimize the possibility of the tool accidentally firing if the tool should be inadvertantly dropped.

An operating handle is attached to the handle of the tool for reciprocal movement therealong. Upon downward movement of the operating handle, the firing mechanism is cocked as well as a fresh cartridge inserted from a cartridge belt into a three chamber cartridge receiving turret. Upward movement of the operating handle results in the extraction of a spent cartridge from the cartridge receiving turret as well as the indexing of the cartridge holding belt into its new position.

At the point wherein the tool is cocked and a fresh cartridge is in proper position in the cartridge receiving portion of the turret, the tool cannot be fired unless the barrel assembly is moved rearwardly to move a trigger link into a position to engage the sear to release it from the hammer when the trigger rod is depressed.

The tool of the present invention is also designed so that the barrel cannot be moved rearwardly unless the operating handle is in its upward position, thereby preventing the tool from being fired unless all the components thereof are in their proper position.

Means are also included to ensure that the operating handle is fully moved in one direction before it can be reversed. This insures that the synchronization of the cartridge feed belt and rotation of the turret does not get out of phase.

DESCRIPTION OF THE DRAWINGS The objects and advantages of the present invention will become more apparent by reference to the follow ing description of a preferred embodiment and to the accompanying drawings in which:

FIG. 1 is a vertical sectional view taken along the lines l1 of FIG. 2 showing the tool in its neutral position after a firing operation;

FIG. 2 is a transverse sectional view taken along the lines 2-2 of FIG. 1;

FIG. 3 is a side view of the tool with the side housing plate removed showing the various components of the tool in their neutral position;

FIG. 4 is a transverse sectional view taken along the lines 4--4 of FIG. 1;

FIG. 5 is a partial sectional view of the tool showing inside of the left-hand side of the housing plate along with the left-hand slide member and pawl and ratchet arrangement thereon;

FIG. 6 is a partial sectional view taken along the lines 66 of FIG. 5;

FIG. 7 is a partial sectional view taken along the lines 7-7 of FIG. 5;

FIG. 8 is a partial sectional view similar to FIG. 7 but showing the pawl and ratchet. assembly in a position permitting upward movement of the operating handle;

FIG. 9 is a transverse sectional view taken along the lines 9-9 of FIG. 1;

FIG. is a partial sectional view similar to FIG. 1 but showing the tool with the operating handle in its down position;

FIG. 1 1 is a view similar to that of FIG. 3. but showing the position of the right-hand slide arm and cam member in their respective positions when the slide handle is in its down position;

FIG. 12 is a view similar to that of FIG. 2 but showing the position of the various components when the operating handle is in its down position;

FIG. 13 is a view similar to that of FIG. 4 but showing the position of the various components when the operating handle is in its down position; and

FIG. 14 is a view similar to that of FIG. 1 but showing the components of the tool in their respective positions when the tool is fully cooked and ready for actuation for a firing operation.

DETAILED DESCRIPTION Referring to the drawings and particularly FIG. 1, the tool of the present invention includes generally a housing 2 having a lower receiver portion 4 in which a barrelassembly 6 is mounted for limited reciprocal motion. As will be noted, the barrel assembly 6 extends forwardly from the housing 2. The housing 2 also includes an upper housing portion 8 to which an elongated handle member 10 is attached and which extends generally perpendicular to the axis of the barrel assembly 6. A trigger rod 12 extends through the interior of the handle member 10 from a point inside the upper housing portion 8 to a point where it protrudes in a button-like fashion from the free end of the handle member 10, thereby forming a trigger button 14. The upper housing portion 8'includes a cocking mechanism indicated generally by 16, which is adapted to actuate the. firing pin mechanism 18 housed within the receiver portion 4 of the housing 2.

A rotatable turret 20 containing three cartridge chamber plugs 22, 24, and 26 is rotatably mounted about its central axis within the receiver portion 4 and is adapted to receive cartridges from a cartridge feed belt 28 and rotate them into alignment with a chamber plug receiving opening 30 in the breech end of the barrel assembly 6.

A feed hub 32 is provided within the receiver portion 4 of the housing 2 rearwardly of the turret 20 to index the cartridge feed belt 28 into its proper position in alignment with two of the three cartridge chamber plugs of the turret 20 for feeding and extraction of a cartridge by means of a feeding and extracting assembly 34. The movement of the feeding and extracting assembly 34 is controlled by means of a cam plate 36 rotatably attached to the right side wall 38 of the housing 2.

The movement of the turret 20, feed hub 32, cam plate 36 and the cocking of the cocking mechanism 16 is controlled'by reciprocal movement of an operating handle 40 mounted on the handle member 10. The operating handle 40 includes two extension arms 42 and 44 which extend through the top plate 46 of the housing 2 and are connected to right and left slide members 48 and 50 respectively by means of a pin 52 or other suitable connection. A pawl and ratchet mechanism 54, associated with the left slide member 50, is

provided to insure that the operating handle is fully It should be noted that for the purpose of this description, the tool is considered to be so orientated that the axis of the elongated handle member 10 extends in a vertical direction. The front of the tool is considered to be the muzzle end of the barrel assembly 6. The left and right sides of the tool are the left and right sides when the tool is viewed from the rear.

More specifically, the elongated handle member 10 is in the form of a first tubular member 56 extending perpendicular to the axis of the barrel assembly 6 and affixed to the upper portion of the housing 2 in any suitable fashion such as by welding or the like. The first tubular portion 56 is threadedly attached to lower grip portion 58 which in turn is connected to a second tubular portion 60. The second tubular portion is connected to an upper grip .portion 62. By having one or more threaded connections along the handle member, the length thereof may be readily changed.

The lower end of the trigger rod 12 is attached to one end of a trigger bar link 64 by means of a suitable connection such as a pin member 66 or the like. The trigger bar link 64 is pivotable about a pin member 68, attached to the housing 2 and located midway of the length of the trigger bar link 64. One end of a trigger bar 70 is attached to the other end of the trigger bar link 64 through a suitable rotatable connection such as a pin member 72 or the like. The other end of the trigger bar contains a generally triangular shaped trigger link 74 pivotably mounted on a suitable pin 78, and spring biased in a counter-clockwise direction as shown in FIG. 1 against a pin 76 into its forward, non-cocking position by a suitable spring member 80.

A sear member 82 having a forwardly extending first finger portion 84 and a downwardly and rearwardly extending second finger 86 is pivotally mounted about a pin 88 attached to the housing 2 of the tool. A suitable spring member 89 biases the sear member in a clockwise direction as viewed in FIG. 1 so that the flat surface 90 of the first finger portion 84 normally rests against a block .92 fixedly attached to the housing 2 and is generally horizontally disposed. The second finger portion 86 extends generally rearwardly and downwardly in the housing 2.

The trigger rod 12, trigger bar link 64 and trigger bar 70 are biased into their neutral position as shown in FIG. 1 by means of a cup-shaped member 91 mounted in a bore 93 in the bottom surface of the top plate 46 which engages the forward end of the trigger bar link 64. A spring member 95 extends from the bottom of the bore 93 to the member 91 to bias the member 91 downwardly. A trigger adjusting screw 97 is threadedly connected to the housing and extends coaxially with the member 91 and is accessible from outside the tool for adjustment.

A hammer member 94 is pivotably mounted on a pin 96 and includes an upwardly extending sear engaging portion 98 and a downwardly extending firing pin engaging portion 100. The hammer member 94 is a socalled rebounding hammer" in that it is normally biased into a neutral position wherein the firing pin engaging portion 100 is slightly spaced from the firing.

pin mechanism 18 by means of a rebound hammer mechanism 102 consisting of atube member 104 having a lower outwardly extending circumferential flange 106 engaging forward and rearward undercuts 108 and 109 in the hammer member 94. The tube 104 has its upper portion extending through a semi-circular floating block 108 mounted in an arcuately shaped portion 110 on the inner surface of the top plate 46 of the housing 2. A pin member 112 extending transversely of the tool is located within a suitable groove 114 extending through the semi-circular block 108. A spring member 116 extends from the semi-circular block 108 to the circumfcrencial flange 106 to bias the tube member 104 downwardly against the hammer member 94.

As mentioned above, the operating handle 40 is mounted on the handle member of the tool and includes two extension arms 42 and 44 which are attached to right and left slide members 48 and 50. Extending transversely in the upper housing portion 8 of the tool and attached to each of the slide members 48 and 50 is a cocking bar 118 which is in vertical alignment with the upperly extending sear engaging portion 98 of the hammer member 94.

The firing pin mechanism 18 is mounted in a block 120 in the receiver portion 4 of the tool and includes a striker portion 122 adapted to engage the rim of the cartridge when the turret is positioned so that a cartridge chamber plug is in the top center position. Attached to the end of the striker portion 122 is an enlarged head portion 124 having a rearward buttonlike extension 126 thereon adapted to be engaged by the firing pin engaging portion 100 of the hammer member 94 when the tool is fired. The firing pin mechanism 18 is biased rearwardly by a suitable spring member 128 so that the enlarged head portion 124 thereof abuts an overlapping screw member 130 and the striker portion 122 is in a position slightly rearward of the turret member 20.

The turret member 20 including its three cartridge chamber plugs 22, 24, and 26 spaced 120 degrees apart, is pivotably mounted within the receiver portion 4 of the housing 2. The turret member 20 is provided with three suitably spaced detent portions 132, 134 and 136 for engagement by pawl members 138 and 140 located on the right and left slide members 48 and 50 in a manner to be explained below. When the tool is in a neutral position as shown in FIG. 1, one cartridge chamber plug 22 of the turret member 20 is in the top center position with its axis lying in a vertical plane passing through the center of the tool and the two other cartridge chamber plugs 24 and 26 having axes which are in a horizontal plane perpendicular to the axis of the handle member 10 of the tool.

As shown in FIG. 2, the right and left hand slide members 48 and 50 contain the pawl members 138 and 140 which engage the detents 133, 134 and 136 on the turret member 20 during operation of the operating handle 40. The pawl member 138 on the right slide member 48 (on the left in view of FIG. 2) comprises a member 142 normally extending upwardly and inwardly and pivoted at its lower end and normally spring biased outwardly until its bottom portion 144 engages a stop surface 146 on the slide member 48. A suitable spring member 148, held in place by two pin members 150 and 152 is mounted in a groove 154 in the slide member 48 with its lower end engaging the upper portion of the member 142 to bias it into its outer position. The actual detent engaging surface comprises a projection 156 extending rearwardly from the upper end of the member 142 as shown by the dotted lines in FIG. 2. This projection 156 on pawl member 138 lies in a vertical plane passing through the detents 132, 134 and 136 of the turret member 20 and is normally positioned inwardly in the tool a sufficient distance to engage the detents. By virtue of the particular construction of this pawl member 138, it will be seen that when the slide member 48 is moved downwardly, this pawl member 138 will be depressed into its groove 154 and pass over the detents of the turret member 20 and be in a position to spring inwardly into a position to engage a detent on the upward movement of the slide member 48.

The pawl member on the left slide member 50 (right side as shown in FIG. 2) consists of a member 158 pivoted at its upper end and extending downwardly and inwardly toward the center of the tool. A spring member 160 mounted in a groove 162 in the slide member 50 by two pin members 164 and 166 acts on the inner surface of the tail portion 168 of the member 158 and biases the member into its inner engaging position until the outer surface of the tail portion 168 engages a stop surface 170 on the slide member 50. As in the case of pawl member 138, the actual detent engaging surface comprises a projection 172 extending from the lower end of the member 158 toward the rear of the tool as shown by the dotted lines in FIG. 2. The projection 172 lies in a vertical plane passing through the detent portion of the turret member 20 and is normally positioned inwardly in the tool a sufficient dis- .tance as to engage the detents. By virtue of the construction of this particular pawl member 138, it will be noted that when the slide member 50 is moved downwardly, it will positively engage one of the detents on the turret member20 and rotate the turret member 20. Upon upward movement of the slide member 50 the pawl member 138 will be depressed into the groove 162 in the slide member 50 and pass over the detent portion of the turret member 211 with no effect thereon.

The upper housing portion 8 is provided with a left and right cartridge feed belt path 174 which are in communication with each other by means of a lower path 176 provided in the receiver portion 4 of the tool by virtue of the feed hub 32 and right and left detent mounting blocks 178 and 180. As will be noted, the lower path 176 is semicircular so that the belt may enter the right side of the tool and be expelled along the left side of the tool.

The feed hub 32 is mounted for rotation about a circular block 182 in the receiver portion 4 of the housing 2 between a neutral position wherein its left stop surface 184 abuts the bottom face of the top plate 187 of the receiver portion and a feeding position wherein its right stop surface 186 is in abutment with the bottom face of the plate 187.. The feed hub 32 is connected to a feed link 188 by a suitable pin connection 190. The feed link 188 is mounted in a suitable groove 191 in the housing 2 and includes a finger portion 192 extending forwardly in th'eitool into a position to be engaged by upper and lower shoulders 194 and 196 on theleft slide member 50.

Two pawl members 198 and 200 are mounted in suitable grooves within the feed hub 32 and are spring biased into the outward position. The pawl members 198 and 200 are so constructed that upon counterclockwise rotation of the feed hub 32 as shown in FIG. 4, they will be depressed into the feed hub 32 and slip over the cartridge belt into a position to engage flat engaging detent surfaces 202 on the cartridge-belt 28 so that upon movement in the opposite direction, they will move the cartridge belt 28 along the feed path.

The cartridge belt 28 includes a plurality of tubular cartridge holding sections 204 interconnected by web portions 205. The interior of each cartridge holding section 204 is generally cylindrical to engage the rim of '7 a cartridge placed therein. The outer surface is generally cylindrical with each section 204 having associated therewith two flat detent surfaces 202, generally perpendicular to the web portion 206, on opposite sides thereof, and facing in opposite directions. This enables either end of the belt 28 to be fed into the tool.

A plurality of detent members 206 and 208 are provided to positively position the cartridge belt 28 so that the lower two cartridge holding sections 204 of the belt 28 are coaxial with the two lower cartridge chamber plugs 24 and 26 of the turret 20. As can be seen in FIG. 4, the right side detent 206 consists of a generally circu lar member 210 having an arcuate surface 212 which is spring biased into the lower feed path 176 by a suitable spring 214 and limited in its inward movement by a pin member 216. The positioning of the pin member 216 is such that the detent 208 will move outwardly out of the feed path 176 upon movement of the cartridge belt 28 in a clockwise direction. When the belt is moved along the feed path, the detent 208 extends into the feed path 176 and engages two adjacent cartridge holding sections of the cartridge belt 28 to hold the belt 28 in its properly indexed position. The left detent member 208 likewise includes an arcuate surface 218 spring biased into the lower feed path by a suitable spring 220 and limited in its inward movement by a pin 22. The detent member 208 engages two adjacent cartridge holding sections of the cartridge belt 28 after the belt 28 has been moved and is cammed out of the feed path 176 when the belt is moved by means of the pawl members 198 and 200 on the feed hub 32.

The feed and extractor assembly 34 is reciprocally mounted within the receiver portion 4 of the housing 2 adjacent the right side wall 38. The feed and extractor assembly 34 includes a rear feed linkage 228 connected to a forward extractor linkage 230 by means of a suitable connection 232. The rear feed linkage 228 includes a forwardly extending feed pin 234 coaxially with the bottom right cartridge chamber plug 24 of the turret member 20. The forward extractor linkage 230 includes a rearwardly extending extractor pin 236 which is coaxial with the bottom left cartridge chamber plug 26 of the turret member 20. In the neutral position of the tool shown in FIG. 11 with the operating handle 40 in its uppermost position, the forward end of the feed pin 234 is positioned rearwardly of the feed belt 28 while the extractor pin 236 extends completely into the bottom left cartridge chamber plug 26 of the turret member 20. When the operating handle 40 is moved downwardly, the feeding and extractor assembly 34 is moved forwardly in the tool until the rearward face of the extractor pin 236 is forward of the cartridge chamber plug 26 and the feed pin 234 extends entirely into the cartridge holding section of the belt 28 which was aligned with the bottom right cartridge chamber plug 24.

The feed and extractor assembly 34 includes a side plate 238 having a vertical slot 240 therein. The cam plate 36, as shown in FIG. 3, is mounted for rotation about a pin 242 fixed to the housing and includes a pin member 244 which extends into the slot 240 in the plate 238 of the feed and extractor assembly 34. The right slide member 48 includes a pin member 246 which extends into a cam track 248 formed within the cam plate 36.

The cam track 248 is so designed that upon downa ward movement of the right slide member 48, the pin member 246 on the slide member will pass through a dwell portion 250 in the cam track 248 during which there is no rotation of the cam plate 36. A generally straight portion 252 follows the dwell portion 250 which, upon downward motion of the slide member 48 is engaged by the pin member 246 to rotate the cam plate counter-clockwise into its position shown in FIG. 11 moving the feed and extractor assembly 34 into its forward position. When the cam member has been rotated so that the pin member 246 is at the circular end 254 of the cam track 248, the cam plate 34 will have been rotated to its position shown in FIG. 11 wherein the axis of the straight portion 252 thereof is in a generally vertical position, thereby providing a lower dwell portion so that further downward movement of the slide member 48 will not cause any rotation of the cam plate 36. This feature is accomplished by virtue of the fact that the perpendicular distance between the axis of the straight portion 252 of the cam track 248 and the center of the fixed pin 242 shown as x in FIG. 3 is the same as the horizontal distance between the center of the fixed pin 242 and the center of the pin 246 of the slide member 48 shown as x.

The barrel assembly 6 is mounted within the receiver portion 4 of the housing 2 and extends forwardly therefrom. The barrel assembly 6 includes a barrel member 256 having a bore 258 therein for the reception of a fastener driving member 260. The chamber plug receiving opening 30 in the rear of the barrel member 256 provides communication with the bore 258 in the barrel member 256 and is of an appropriate diameter to telescope over the top center cartridge chamber plug 22 of the turret 20. The barrel assembly 6 also includes a forwardly extending barrel extension 262 having a bore 264 therein which tapers inwardly and forwardly to reduced bore 265 having a diameter of an approximate size to contain a fastener member 266.

The fastener driving member 260 includes an enlarged head portion 268 adapted to ride within the larger portion of the bore of the barrel assembly 6 and a reduced forwardly extending portion 270 adapted to extend into the reduced bore 265 of the barrel assembly 6.

A washer guide member 272 is threadedly attached to the forward barrel extension 262 and includes an enlarged flange portion 274 having a bore 275 therein of a sufficient size to contain the enlarged washer 276 of the fastener member 266 to be set. A band spring member 278 surrounds the outer surface of the flange portion 114 and has one end 280 turned into the bore 275 to frictionally engage the washer 276. The barrel assembly 6 is spring biased into its forward position whereat a shoulder 282 on the barrel extension 262 engages a horizontally extending lug 284 in the housing 2 by a springg member 286 extending between the forward face 288 of the housing and the rearward surface 290 of the enlarged flange portion 274 of the washer guide member 272.

The right outer side of the barrel member 256 is provided with a rearwardly facing shoulder 292. The side plate 238 of the feed and extractor assembly 34 has a cutout 294 therein which provided a forwardly facing shoulder 296 which will be engaged by the shoulder 292 on the barrel member 256 in the event that the barrel assembly 6 is moved rearwardly when the feed and extractor assembly 34 is not in its complete rearward position.

As shown in FIG. 9, the bottom surface of the barrel member 256 includes two arcuate grooves 298 and 300 to provide clearance for the barrel assembly 6 to move rearwardly past the bottom two cartridge chamber plugs of the turret member 20 as the end of the barrel assembly 6 telescopes over the top cartridge chamber plug of the turret member 20. In addition, a slot 304 is provided in the bottom surface of the barrel member 256 into which a projection 208 on the feed and extractor assembly 34 extends to provide guidance for the barrel assembly 6.

The upper surface of the barrel member 256 is provided with an axially extending slot 310 terminating in a rearwardly facing shoulder 312. A trigger connector 314 is mounted on pins 316 in the upper housing portion 8 and includes a finger 318 extending downwardly through the top plate of the receiver portion 4 into the slot 310 in the top of the barrel member 256. Horizontally extending slots 320 in the trigger connector 314 permit the trigger connector 314 to move in a direction parallel to the axis of the barrel assembly 6. An upstanding projection 322 on the trigger connector 314 is engaged by the trigger link 74 due to the spring member 80 in the trigger bar 70 tending to rotate the trigger link 74 in a counter-clockwise direction as shown in FIG. 1, moving the trigger connector 314 into its forward position.

FIGS. -8 show the pawl and ratchet mechanism 54 which prevents the operator from not completing a full cycle of the operating handle 40. A pawl housing 324 is pivotably connected to the left slide member 50 by means of a pivot pin 326. A rack member 328 having a plurality of teeth 330 is attached to the inner side of the left housing plate 332 by means of a pivot pin 334 adjacent the bottom end and a screw member 336 extending through the left side plate adjacent the upper end. The rack member 328 has its upper end turned outwardly and projects through an opening in the top plate 46 of the housing 2 so that it can be reached from the outside of the tool. The intermediate portion of the ratchet member is spaced inwardly from the side wall and is contained within a groove 338 in a block 340. Mounted between the block 340 and the side plate 332 is an outer spring member 342 having its lower end 344 inturned against the rack member 328. Mounted on top of the block 340 is an inner spring member 346, which has its upper end 347 turned outwardly against the rack member 328. A projection from the block 340 between the outer spring member 342 and the rack member 328 provides an outer and inner track 348 and 350.

The pawl housing 324 includes inner and outer spaced plates 352 and 354 between which are mounted upper and lower pawl members 356 and 358 in overlapping relationship. The inner most pawl member 356 extends upwardly in the tool and terminates in a flat tooth engaging surface 360. The upper pawl member 360 also consists of a curved surface 362 for permitting the pawl member to ride over the teeth 330 of the rack member 328 when the slide member 50 is is moved downwardly. A spring member 364 biases the upper pawl member 356 into its outer position. The outer pawl member 358 extends downwardly in the tool and includes a flat tooth engaging surface 366 and a curved surface 368 the latter of which permits the pawl member 358 to ride over the teeth 330 of the rack member 328 when the slide member 50 is moved upwardly. A suitable spring member 368 biases the lower pawl member 358 into its outer most portion.

As can be seen in FIG. 6, the inner plate 352 of the pawl housing 324 extends into the area between the inner spring member 346 and the rack member 328 while the outer plate member 354 extends into the area between the outer spring member 342 and the rack member 328. It is to be noted that the block 340 and therefore the projection forming the tracks 348 and 350 does not extend the entire length of the rack member 328. The ends 344 and 348 of each of the spring members 342 and 346 are so positioned so that they will be in engagement with their respective plate members just before and after the outer plate member has cleared the tracks.

When the slide member 50 is in its upper most position, the end of the inner spring member 346 engages the inner plate member 352 and forces the pawl housing 324 into its outer position, whereupon the upper pawl member 356 is in engagement with the teeth 330 of the rack member 228 and the outer plate member 354 is in alilgnment with the outer track 348. The lower pawl member 358 is positioned outwardly of the rack member 328 out of engagement with the teeth thereon. Due to the curved surface 362 of the upper pawl member 356, when the slide member 50 is moved downwardly carrying the pawl housing 324 along with it, the upper pawl member 356 will ratchet along the teeth 330 of the rack member 328.. However, in the event that the operator tries to reverse the action of the slide member 50 before it reaches the end of the downward stroke, the flat surface 360 of the upper pawl member 356 will engage one of the teeth 330 preventing upward movement of the slide member 50.

When the slide member 50 reaches the end of its downward stroke, the inturned end 344 of the outer spring member 42 engages the outer plate member 354 causing the pawl housing 324 to pivot inwardly until the outer plate 354 is in alignment with the inner track 350 and the lower pawl 358 is in engagement with the teeth of the rack member 328. The upper pawl member 356 is positioned inwardly of the rack member 328 out of engagement with the teeth 330 thereof. Due to the curved surface 368 of the lower pawl member 358, the slide member 50 can move upwardly and the pawl member 358 will ratchet over the teeth 330 of the rack member 328. The position of the components during the upward motion of the slide member 50 is shown in FIG. 8. However, if the operator tried to reverse the action of the slide member 50 before the end of the upward movement, the flat surface 366 of the pawl member 358 would engage a tooth of the rack member and prevent the downward movement of the slide member 50. Thus, it can be seen that once the movement of the slide member 50 and therefore the operating handle 40 is started in either direction, that movement must be completed before the direction of movement can be reversed.

In the event that a jam occurred in the tool and it was necessary to reverse the movement of the slide member 50 in the middle of a stroke, the rack member 328 can be moved out of engagement with either of the pawl members 356 and 358 by removing the top screw member 336 and pivoting the rack member 328 about the bottom pivot pin 334 in a clockwise direction as shown in FIG. 5. a

In order to operate the tool, an appropriate fastener member 266 must be inserted into the muzzle end of the barrel assembly 6. The insertion of the fastener pin 266 moves the fastener driving member 260 into its rearward position with the head portion 268 adjacent the chamber plug receiving opening 30. After a firing operation and upon insertion of a fastener member, the components of the tool are positioned as shown in FIG. 1 with a spent cartridge 380 located within the top center cartridge chamber plug 22 of the turrent member and a live cartridge 382 positioned in the belt 28 in alignment with the bottom right cartridge chamber plug 24. The cartridge holding section of the belt 28 in alignment with the bottom left cartridge chamber plug 26 of the turret member 20 is empty. The feed and extractor assembly 34 is in its rearward position.

The operator must then push the operating handle 40 down. As he does, the right and left slide members 48 and 50 and the cocking bar 118 move downwardly as a unit. During the initial movement of the operating handle 40, the pin member 246 on the right slide member 48 passes through the dwell portion 250 of the cam track 248 during which there is no rotation of the cam plate 30. After the initial dwell, further downward movement of the slide arms causes rotation of the cam plate 30 and starts the forward movement of the feed and extractor assembly 34. As the feed and extractor assembly 34 moves forwardly, the feed pin 234 rams the cartridge 382 from the belt 28 into the lower right cartridge chamber plug 24 of the turret member 20 and the extractor pin 277 withdraws from the lower left cartridge chamber plug 26. At this point, the cam plate 36 is in its lower dwell position so that there is no further movement of the cam plate 32 and the feed and extractor assembly 34 remains stationary in its forward position during the remainder of the downward movement of the operating handle 40.

Continued downward movement of the operating handle 40 results in the pawl 140 on the left slide member 50 (right hand sideas shown in FIG. 2) engaging the detent 132 on the turret member 20 and rotating the turret member 20 approximately 60 degrees or one-half of its indexing rotation. In addition,the cocking bar 118 contacts the hammer member 94 causing the upperly extending portion 98 to pass under the second finger 86 of the sear member 82 which holds the hammer member 94 in its cocked position as shown in FIG. 10.

As the slide members 48 and 50 approach the bottom of their stroke, the upper shoulder'194 of the left hand slide member engages the finger portion 192 on the feed link 188 and the feed link 188 is moved downward from its position as shown in FIG. 4 causing the feed hub 32 to rotate counter-clockwise into its position as shown in FIG. 13. At the bottom of the stroke, the pawl members 198 and 200 on the feed hub 32 are in a position to engage the detent surface 202 of the cartridge holding section 204 of the cartridge belt 28 immediately rearward of the ones they were previously in engagement with.

Thus, at the end of a downward stroke of the operating handle 40, the hammer member 94 has been moved into its cocked position. The feed pin 234 has inserted a cartridge into the lower right cartridge chamber plug 24 of the turret member 20 and the turret member has been rotated 60 degrees or one-half of its indexing rotation. In addition, the pawl member 138 on the right slide member 48 has been positioned underadetent 134 on the turret member 20 and the feed hub 32 has been rotated in a position to engage a new set of belt detent surfaces 202.

As the operating handle 40 is moved up, there is an 48 engages the detent 134 on the'turret member 20 and indexes the turret member 20 the second half of its index rotation, approximately 60, whereupon the original lower right cartridge chamber plug 24, which had a live cartridge 382 placed therein during the downward movement of the operating handle 40 is now in the top center position in line for firing. At this point the dwell is over and the cam plate 36 is rotated clockwise as viewed in FIG. 11 to move the feed and extractor assembly 34 rearwardly. This action causes the feed pin 234 to withdraw from the cartridge belt 28 and the extractor pin 263 enters the cartridge chamber plug 22 containing the spent cartridge 380 and which is now in the lower left position. This action of the extractor pin 236 causes the spent cartridge 380 to be reinserted into the open cartridge holding section of the cartridge belt 28.

After the feed and extractor assembly 34 reaches its rearward position, the cam plate 36 is in its dwell position. Further upward movement of the operating handle 40 results in the lower shoulder 196 on the left slide member 50 contacting the finger portion 192 of the feed link 188 and pulling the feed link 188 upwardly causing the feed hub 32 to rotate in a clockwise direction as viewed in FIG. 13. Due to the engagement of the pawl members 198 and 200 with the detent surface 202 on the cartridge belt 28 this rotation of the feed hub 32 causes the belt 28 to be moved into its next position wherein a fresh cartridge is in alignment with the car tridge chamber plug 26 now in the bottom right position and the now empty cartridge holding section 204 of the belt which had held the live cartridge 282 is in line with cartridge chamber plug 22 now in the bottom left position.

It is noted that at this point the barrel assembly 6 is still in its forward position with the trigger link 74 rotated into its forward most position. Thus, even if the trigger rod 12 is depressed, causing the trigger bar link 64 to rotate counterclockwise and the trigger bar to be moved upwardly, the sear member 82 will not be released from engagement with the hammer member 94 because of the vertical distance between the trigger link 74 and the forwardly extending first finger 84 of the sear member 82. This prevents the tool from being fired-unless the barrel assembly 6 is moved rearwardly.

When the barrel assembly is moved rearwardly by pushing the tool against a work surface such as an insulating panel 384 to be attached to the wall 386 of an ingot mold, the shoulder 312 on the top surface of the barrel member 256 engages the trigger connector 314 and moves the trigger connector 314 rearwardly as the chamber receiving opening 30 in the barrel assembly 6 telescopes over the top center cartridge chamber plug 24 of the turret member 20. The rearward movement of the trigger connector 314 causes the trigger link 74 to rotate clockwise into a position immediately below the forward extending finger 84 of the sear member 82 At this point, when the trigger rod 12 is depressed, causing the trigger bar link to pivot about the fixed pin and the trigger bar 70 to be raised upwardly in a vertical direction, the trigger link 74 will engage the sear member 82 causing it to rotate counter-clockwise releasing the hammer member 94 which rotates counterclockwise under the influence of the spring member 116 and rams the head portion 124 of the firing pin mechanism 18 causing the striker portion 122 thereof to strike the cartridge 382 and cause the ignition 13 thereof. Upon ignition of the cartridge 382, the gases act upon the rearward face of the head portion 268 of the fastener driving member 260 driving it forward which in turn drives the fastener member 266 into the work surface. The above described procedure is then repeated for the next firing operation.

The trigger adjustment screw 97 provides an adjustment to ensure that the tool cannot be fired unless the barrel assembly is completely telescoped over the top center cartridge chamber plug of the turret member 20. It is conceivable, due to various tolerances, that there will be enough room for sufficient upward movement of the trigger bar 70 so that even if the trigger connector 314 is not completely moved rearwardly to rotate the trigger link 64 so that the sear engaging portion thereof is immediately below the first finger portion 84, the trigger link 74 can be raised a sufficient distance to release the sear member 82. This possibility can be prevented by screwing the trigger adjustment screw 97 into the tool so that it holds the cup-shaped member 91 against the trigger bar link 64. This will prevent any movement of the trigger rod 12 and thus, prevent firing of the tool. The tool can be cocked and the barrel assembly 6 moved rearward, and the screw backed off until there is sufficient movement of the member 91 to permit sufficient movement of the trigger rod 12 to release the sear.

To substantially minimize any chance of the tool accidentally firing if dropped when cocked, the moments of the trigger rod 12 and trigger bar 70 about the pin member 68 of the trigger bar link 64 are equal. By moment is meant the mass of the trigger rod and trigger bar times their moment arms, or distance from the pin member 68. As the pin member 68 is located substantially halfway between the trigger rod 12 and the trigger bar 70, their moment arms are substantially equal. Therefore, in order for their moments to be equal, the mass of the trigger rod 12 and that of the trigger bar 70, including any components attached thereto, are equal. Therefore, any inertia force tending to move the trigger bar 70 in an upward direction and causing the trigger bar link 64 to rotate counter-clockwise will be offset by the same inertia force tending to move the trigger rod 12 in the same direction but causing the trigger bar link 64 to rotate clockwise.

The detent members 206 and 208 provide positive engagement with the cartridge belt 28 to hold the belt 28 in its proper indexed position. When the operating handle 40 is in its up position, the feed and extractor assembly 34 is in its rearward position with the extractor pin 236 positioned in the bottom left cartridge chamber plug of the turret member 20. This holds the turret member in its properly indexed position so that the top center cartridge chamber plug is aligned with the opening 236 in the barrel assembly 6 so that the rear of barrel assembly 6 can be telescoped over the top center cartridge chamber plug upon rearward movement of the barrel assembly 6.

What is claimed is:

1. A powder-actuated tool comprising a housing, means in said housing for providing a path for a cartridge belt having a plurality of cartridge holding sections, cartridge holding means moveable in said housing and including at least one cartridge holding portion for receiving a cartridge from the cartridge belt, a barrel assembly having an opening therein for receiving at least a portion of said cartridge holding portion, means for moving said cartridge holding means from a first position whereat the cartridge holding portion receives a cartridge from said cartridge receiving belt to a second position when said cartridge holding portion is in alignment with said opening in said barrel assembly and to a third position whereat the cartridge holding portion is in alignment with an empty cartridge holding section of the belt, and means for moving said belt from a position wherein a cartridge holding section having a cartridge therein is in alignment with the cartridge holding portion of said cartridge holding means when the cartridge holding means is in said first position to a position wherein an empty cartridge holding section is in alignment with the cartridge holding portion of the cartridge holding means when said cartridge holding means is in its third position.

2. The powder-actuated tool of claim 1 further including means for feeding a cartridge from the cartridge belt into the cartridge holding portion of said cartridge holding means when said cartridge holding means is in its first position, means for firing a cartridge in said cartridge holding portion when said cartridge holding means is in its second position, and means for extracting the spent cartridge from said cartridge hold- -ing portion into an empty cartridge holding section of the cartridge belt when said cartridge holding means is in its third position.

3. The powder-actuated tool. of claim 2 wherein said cartridge holding means includes a rotatable turret member having three cartridge receiving plugs therein, said means for moving said cartridge holding means presenting each of said cartridge receiving plugs alternately to each of the three positions of said cartridge holding means.

4. The powder-actuated tool of claim 1 further including an elongated handle attached to said housing and extending generally perpendicular to the axis of the barrel assembly and wherein the means for moving said cartridge holding means and the cartridge belt includes an operating handle mounted on the elongated handle and reciprocal in the direction of the axis of the elongated handle.

5. The powder-actuated tool of claim 4 wherein said cartridge holding means includes a rotatable turret member having three cartridge receiving plugs therein, and further including first and second slide members connected to said operating handle for movement therewith, a pawl member on each of said slide member, detent means on said turret member for engagement by one of said pawl members upon movement of said operating handle in one direction to rotate said turret member about one-half the distance between two successive positions and engagement by the other of said pawl members upon opposite movement of said operating handle to rotate the turret member the remainder of the distance between the two successive positions.

6. The powder-actuated tool of claim 5 wherein said means for moving the cartridge belt includes a feed hub rotatable about an axis and having at least one cartridge belt engaging pawl thereon.

7. The powder-actuated tool of claim 6 wherein said feed hub has a feed link thereon, means on one of said slide arms to engage said feed link to rotate said feed hub in one direction upon movement of said operating handle in said one direction and to engage said feed link to rotate said feed hub in the opposite direction upon movement of said operating handle in said opposite direction whereby said bel't engaging pawl engages the belt to move it to its next successive position.

8. The powder-actuated tool of claim 4 further including a feed and extractor assembly reciprocal between a first rearward position and a second forward position, means on said assembly to feed a cartridge from the belt to said cartridge holding portion upon movement of said assembly from its first position to its second position, and means on said assembly to eject a spent cartridge from said cartridge holding portion into the belt upon movement of said assembly from its second position to its first position.

9. The powder-actuated tool of claim 8 further including a slide member connected to said operating handle, a cam plate rotatably mounted on said housing and including feed and extractor assembly engaging means, a track extending generally parallel to the axis of said elongated handle on said assembly for engagement by said assembly engaging means, cam engaging means on said slide member for engagement with said cam plate, a cam track means in said cam plate for engagement by cam engaging means for imparting motion to said cam plate to move said assembly from its first to its second position upon movement of said operating handle in one direction and from its second to its first position upon movement of said operating handle in the opposite direction. 7 10. The powder-actuated tool of claim 9 where said means for moving said cartridge holding means includes means connected to said operating handle for moving said cartridge holding means a portion of the distance between successive positions upon movement of said operating handle in one direction and for moving said cartridge holding means the remainder of the distance between successive positions upon movement of said operating handle in the other direction, said means for moving said belt including means connected to said operating handle for moving into belt advancing position upon movement of said operating handle in said one direction and for advancing the belt into its next successive position upon movement of said operating handle in said opposite direction, the movement of said cartridge holding means, the belt and the feed and extractor assembly being so synchronized that upon movement of said handle in one direction the feed and extractor assembly is moved from its first position to its second position prior to any movement of said cartridge holding means and said belt and said assembly is held in said second position as said means for moving the belt is moved into its belt advancing position and said cartridge holding means is moved the first portion of the distance between successive positions, and upon movement of said operating handle in said opposite direction, said assembly is held in said second position until said cartridge holding means is moved the remainder of the distance between successive positions and then moved from its second position to its first position prior to the belt being moved to its next successive position.

11. The powder actuated tool of claim 10 further including means interposed between said housing and said operating handle for preventing the reversal of said movement of said operating hanlde during movement in one of said directions until the movement in that direction is completed and preventing reversal of movement of said operating handle during movement in the other of said directions until the movement in that direction is completed.

12. The powder-actuated tool' of claim 11 wherein said means for preventing the reversal of movement of said operating handle includes a pawl mechanism associated with said operating handle and a rack member associated with said housing and positioned for engagement by said pawl mechanism.

13. The powder actuated tool of claim 10 further including firing pin means for actuating a cartridge, said firing pin means being moveable between a firing position and a cocked position and means responsive to said movement of the operating handle for moving said firing pin means into said cocked position upon movement of said operating handle in said one direction.

14. The powder-actuated tool of claim 10 wherein said cartridge holding means includes a rotatable turret having three cartridge receiving plugs therein, said feed and extractor assembly including a feed pin for ejecting a cartridge from the belt into one of said plugs upon movement of said assembly from its first position to its second position, and an extractor pin for ejecting a spent cartridge from one of said plugs into said belt upon movement of said assembly from said second position to said first, said pin being positioned within one of said plugs when said assembly is in its first position.

15. The powder-actuated tool of claim 14 further including means in said housing for releasably holding said belt in a given position after said belt has been moved into each of its positions.

16. In a powder-actuated tool, a cartridge belt for holding a plurality of cartridges to be fed into said tool, means for removing a cartridge from said belt for transfer into a position to be fired, and means for returning the spent cartridge into the belt after the cartridge has been fired.

17. In a powder-actuated tool, a housing, a cartridge belt feed path in said housing, and means for extracting a cartridge from said belt, means for returning a spent cartridge to said belt, and means for indexing said belt from a first position wherein a cartridge is extracted therefrom to a second remote position wherein a spent cartridge is inserted thereinto.

18. A powder-actuated tool including a housing, a barrel assembly mounted in said housing, an elongated tubular handle extending from said housing and having an axis of elongation extending transversely to the axis of the barrel assembly, means for holding a powdercharge to be fired, firing means in said housing for firing said powder-charge, means for moving said firing means into its cocked position, means including a sear for holding said firing means in its cocked position, and means for releasing said sear for holding engagement with said firing means to fire the tool, said means for releasing including a trigger rod extending through said handle and having one end protruding from the free end thereof, a trigger bar link pivoted at a pivot point to said housing and extending transversely of the axis of said handle, the other end of said trigger rod being attached to said trigger bar link on one side of said pivot point, a trigger bar having one end thereof attached to said trigger bar link on the other side of said pivot point and extending transversely of the axis of the barrel assembly, means on said trigger bar link for engagement with said sear to release it from holding engagement from said firing means upon movement of said trigger rod toward said barrel assembly, said trigger rod and said trigger bar having equal moments.

19. A powder-actuated tool including a housing, a barrel assembly extending therefrom and moveable between a forward nonfiring position, and a rearward firing position, means for holding a powder-charge in a position to be fired, firing means in said housing for firing said powder charge, means for cocking said firing means, means for holding said firing means in said cocked position, including a scar member, actuating means for releasing said sear member from holding engagement with said firing means to fire said tool, said actuating means including a pivotal member for contacting said sear to release it and means for moving said pivotal member into contact with said sear to cause the release thereof, means normally biasing said pivotal member out of firing position to contact said sear and release it even if said means for moving said pivotal member is actuated, and means responsive to the movement of said barrel assembly into its rearward position to move said pivotal member into a firing position to contact said sear and release it when said means for moving said sear is actuated and said barrel assembly is in its rearward position.

20. The powder-actuated tool of claim 19 wherein said barrel assembly includes a shoulder thereon, said means responsive to the movement of said barrel assembly includes a connector member mounted for limited reciprocal movement in a direction parallel to the axis of the barrel assembly, said pivotal member contacting said connecting member and holding it in its forward position when said pivotal member is out of firing position, means on said. pivotal member for engagement by said shoulder upon rearward movement of said barrel assembly to move said pivotal member into said firing position when said barrel assembly is in its rearward position.

21. In a powder actuated tool, a housing, a barrel assembly mounted in said housing, a turret member having at least one cartridge holding plug, means rotatably mounting said turret member so that said cartridge holding plug is rotatable about an axis parallel to the axis of the barrel assembly, said barrel member having an opening therein for telescoping over said plug when said plug is in alignment therewith, and means for indexing said turret member from a first position wherein said cartridge holding plug is out of alignment with said opening in said barrel to a second position wherein said plug is in alignment with said opening in said barrel.

Q UNHED SKATES PATENT @FFICE QER'HMQATE @F @QRRECHQN Pa 3, 929, 269 Dated December 30, 1975 Q In ent -r(s) Elmer R0 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

O Col. 1, line 35, please delete "toll" and insert tool;

Col. 5, line 49, please delete "133" and insert -l32--; Col. 7, line 26, please delete "22" and insert -222--; Col. 8, line 54, please delete "springg" and insert -spring--; Col. 9, line 7, please delete "208" and insert --308-;

fiigmd and %taicd this Third Day 0? August 1976 [SEAL] O Attest.

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ofParents and Trademarks 

1. A powder-actuated tool comprising a housing, means in said housing for providing a path for a cartridge belt having a plurality of cartridge holding sections, cartridge holding means moveable in said housing and including at least one cartridge holding portion for receiving a cartridge from the cartridge belt, a barrel assembly having an opening therein for receiving at least a portion of said cartridge holding portion, means for moving said cartridge holding means from a first position whereat the cartridge holding portion receives a cartridge from said cartridge receiving belt to a second position when said cartridge holding portion is in alignment with said opening in said barrel assembly and to a third position whereat the cartridge holding portion is in alignment with an empty cartridge holding section of the belt, and means for moving said belt from a position wherein a cartridge holding section having a cartridge therein is in alignment with the cartridge holding portion of said cartridge holding means when the cartridge holding means is in said first position to a position wherein an empty cartridge holding section is in alignment with the cartridge holding portion of the cartridge holding means when said cartridge holding means is in its third position.
 2. The powder-actuated tool of claim 1 further including means for feeding a cartridge from the cartridge belt into the cartridge holding portion of said cartridge holding means when said cartridge holding means is in its first position, means for firing a cartridge in said cartridge holding portion when said cartridge holding means is in its second position, and means for extracting the spent cartridge from said cartridge holding portion into an empty cartridge holding section of the cartridge belt when said cartridge holding means is in its third position.
 3. The powder-actuated tool of claim 2 wherein said cartridge holding means includes a rotatable turret member having three cartridge receiving plugs therein, said means for moving said cartridge holding means presenting each of said cartridge receiving plugs alternately to each of the three positions of said cartridge holding means.
 4. The powder-actuated tool of claim 1 further including an eloNgated handle attached to said housing and extending generally perpendicular to the axis of the barrel assembly and wherein the means for moving said cartridge holding means and the cartridge belt includes an operating handle mounted on the elongated handle and reciprocal in the direction of the axis of the elongated handle.
 5. The powder-actuated tool of claim 4 wherein said cartridge holding means includes a rotatable turret member having three cartridge receiving plugs therein, and further including first and second slide members connected to said operating handle for movement therewith, a pawl member on each of said slide member, detent means on said turret member for engagement by one of said pawl members upon movement of said operating handle in one direction to rotate said turret member about one-half the distance between two successive positions and engagement by the other of said pawl members upon opposite movement of said operating handle to rotate the turret member the remainder of the distance between the two successive positions.
 6. The powder-actuated tool of claim 5 wherein said means for moving the cartridge belt includes a feed hub rotatable about an axis and having at least one cartridge belt engaging pawl thereon.
 7. The powder-actuated tool of claim 6 wherein said feed hub has a feed link thereon, means on one of said slide arms to engage said feed link to rotate said feed hub in one direction upon movement of said operating handle in said one direction and to engage said feed link to rotate said feed hub in the opposite direction upon movement of said operating handle in said opposite direction whereby said belt engaging pawl engages the belt to move it to its next successive position.
 8. The powder-actuated tool of claim 4 further including a feed and extractor assembly reciprocal between a first rearward position and a second forward position, means on said assembly to feed a cartridge from the belt to said cartridge holding portion upon movement of said assembly from its first position to its second position, and means on said assembly to eject a spent cartridge from said cartridge holding portion into the belt upon movement of said assembly from its second position to its first position.
 9. The powder-actuated tool of claim 8 further including a slide member connected to said operating handle, a cam plate rotatably mounted on said housing and including feed and extractor assembly engaging means, a track extending generally parallel to the axis of said elongated handle on said assembly for engagement by said assembly engaging means, cam engaging means on said slide member for engagement with said cam plate, a cam track means in said cam plate for engagement by cam engaging means for imparting motion to said cam plate to move said assembly from its first to its second position upon movement of said operating handle in one direction and from its second to its first position upon movement of said operating handle in the opposite direction.
 10. The powder-actuated tool of claim 9 where said means for moving said cartridge holding means includes means connected to said operating handle for moving said cartridge holding means a portion of the distance between successive positions upon movement of said operating handle in one direction and for moving said cartridge holding means the remainder of the distance between successive positions upon movement of said operating handle in the other direction, said means for moving said belt including means connected to said operating handle for moving into belt advancing position upon movement of said operating handle in said one direction and for advancing the belt into its next successive position upon movement of said operating handle in said opposite direction, the movement of said cartridge holding means, the belt and the feed and extractor assembly being so synchronized that upon movement of said handle in one direction the feed and extractor assembly is moved from its first position to its second posiTion prior to any movement of said cartridge holding means and said belt and said assembly is held in said second position as said means for moving the belt is moved into its belt advancing position and said cartridge holding means is moved the first portion of the distance between successive positions, and upon movement of said operating handle in said opposite direction, said assembly is held in said second position until said cartridge holding means is moved the remainder of the distance between successive positions and then moved from its second position to its first position prior to the belt being moved to its next successive position.
 11. The powder actuated tool of claim 10 further including means interposed between said housing and said operating handle for preventing the reversal of said movement of said operating hanlde during movement in one of said directions until the movement in that direction is completed and preventing reversal of movement of said operating handle during movement in the other of said directions until the movement in that direction is completed.
 12. The powder-actuated tool of claim 11 wherein said means for preventing the reversal of movement of said operating handle includes a pawl mechanism associated with said operating handle and a rack member associated with said housing and positioned for engagement by said pawl mechanism.
 13. The powder actuated tool of claim 10 further including firing pin means for actuating a cartridge, said firing pin means being moveable between a firing position and a cocked position and means responsive to said movement of the operating handle for moving said firing pin means into said cocked position upon movement of said operating handle in said one direction.
 14. The powder-actuated tool of claim 10 wherein said cartridge holding means includes a rotatable turret having three cartridge receiving plugs therein, said feed and extractor assembly including a feed pin for ejecting a cartridge from the belt into one of said plugs upon movement of said assembly from its first position to its second position, and an extractor pin for ejecting a spent cartridge from one of said plugs into said belt upon movement of said assembly from said second position to said first, said pin being positioned within one of said plugs when said assembly is in its first position.
 15. The powder-actuated tool of claim 14 further including means in said housing for releasably holding said belt in a given position after said belt has been moved into each of its positions.
 16. In a powder-actuated tool, a cartridge belt for holding a plurality of cartridges to be fed into said tool, means for removing a cartridge from said belt for transfer into a position to be fired, and means for returning the spent cartridge into the belt after the cartridge has been fired.
 17. In a powder-actuated tool, a housing, a cartridge belt feed path in said housing, and means for extracting a cartridge from said belt, means for returning a spent cartridge to said belt, and means for indexing said belt from a first position wherein a cartridge is extracted therefrom to a second remote position wherein a spent cartridge is inserted thereinto.
 18. A powder-actuated tool including a housing, a barrel assembly mounted in said housing, an elongated tubular handle extending from said housing and having an axis of elongation extending transversely to the axis of the barrel assembly, means for holding a powder-charge to be fired, firing means in said housing for firing said powder-charge, means for moving said firing means into its cocked position, means including a sear for holding said firing means in its cocked position, and means for releasing said sear for holding engagement with said firing means to fire the tool, said means for releasing including a trigger rod extending through said handle and having one end protruding from the free end thereof, a trigger bar link pivoted at a pivot point to said housing and extending transversely of tHe axis of said handle, the other end of said trigger rod being attached to said trigger bar link on one side of said pivot point, a trigger bar having one end thereof attached to said trigger bar link on the other side of said pivot point and extending transversely of the axis of the barrel assembly, means on said trigger bar link for engagement with said sear to release it from holding engagement from said firing means upon movement of said trigger rod toward said barrel assembly, said trigger rod and said trigger bar having equal moments.
 19. A powder-actuated tool including a housing, a barrel assembly extending therefrom and moveable between a forward nonfiring position, and a rearward firing position, means for holding a powder-charge in a position to be fired, firing means in said housing for firing said powder charge, means for cocking said firing means, means for holding said firing means in said cocked position, including a sear member, actuating means for releasing said sear member from holding engagement with said firing means to fire said tool, said actuating means including a pivotal member for contacting said sear to release it and means for moving said pivotal member into contact with said sear to cause the release thereof, means normally biasing said pivotal member out of firing position to contact said sear and release it even if said means for moving said pivotal member is actuated, and means responsive to the movement of said barrel assembly into its rearward position to move said pivotal member into a firing position to contact said sear and release it when said means for moving said sear is actuated and said barrel assembly is in its rearward position.
 20. The powder-actuated tool of claim 19 wherein said barrel assembly includes a shoulder thereon, said means responsive to the movement of said barrel assembly includes a connector member mounted for limited reciprocal movement in a direction parallel to the axis of the barrel assembly, said pivotal member contacting said connecting member and holding it in its forward position when said pivotal member is out of firing position, means on said pivotal member for engagement by said shoulder upon rearward movement of said barrel assembly to move said pivotal member into said firing position when said barrel assembly is in its rearward position.
 21. In a powder actuated tool, a housing, a barrel assembly mounted in said housing, a turret member having at least one cartridge holding plug, means rotatably mounting said turret member so that said cartridge holding plug is rotatable about an axis parallel to the axis of the barrel assembly, said barrel member having an opening therein for telescoping over said plug when said plug is in alignment therewith, and means for indexing said turret member from a first position wherein said cartridge holding plug is out of alignment with said opening in said barrel to a second position wherein said plug is in alignment with said opening in said barrel. 